Optimization of sidewall roughness in silica waveguides to reduce the propagation losses

Summary form only given. The propagation loss of silica waveguide is mainly due to the nonuniformities arising from the film deposition and etching process. Especially, scattering from the sidewall roughness (SWR) is the main cause of the propagation loss. Smooth sidewall offers lower propagation loss and reduced sensitivity to polarization. In this work SWR and etched profile of silica waveguides fabricated by dry etching were investigated. Fabrication techniques to form waveguides with vertical and smooth sidewall were suggested.